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A.
Ground Loop Installation
A
Ground
Loop
system recirculates
the
same antifreeze
solution through
a
closed system
of
high-density
underground polyethylene
pipe.
As
the solution
passes
through
the
pipe.
it
collects
energy
(in
the heating mode)
from the relatively warm
surrounding
soil
through
the
pipe
and
into
the
relatively
cold
solution.
The
solution
circulates
to
the
heat
pump,
which
transfers energy out
of
the solution, and then the
solution
circulates back throush
the
ground to extract more
energy.
The
GeoSource
2000
is
designed
to
operate
on
either
vertical
or
horizontal ground
loop
applications. Vertical
Ioops are
typically
installed
with
a
well drilling
rig
up
to
200 feet
deep,
or more.
Horizontal
loops
are
installed
with
excavating
or
trenchin,e
equipment
to
a
depth
of
about six
to eight feet, depending on
geo_sraphic
location
and
len-eth
of
pipe
used.
Loops must
be
sized
properly
for
each
particular geographic area,
soil type, and
individual
capacity
requirements.
Contact
ECONAR's
Customer
Support
or
the
local installer
for
loop
sizing requirements
in your
area.
Typical winter
operating
EWT to
the
heat
pump
ranges
from
25"F to
32"F.
VCAUTION
-
Ground Loops
musr
be properly
freeze
protected.
Insufficient
amounts
of
antifreeze may result
in
a
freeze
rupture
of
the
unit or
can
cause
unit
shutdown
problems
during cold
wearher
operation. propylene
glycol
and
Geothermal Transfer
Fluid (GTF) are
common
antifreeze
solutions.
GTF
is
a
methanol-based antifreeze
and should be mixed
50Vo
with
water
to
achieve
freeze
protection
of
12oF.
Propylene
glycol
antifreeze
solution
should
be
rixed
25Vo
with
water
to obtain
a
15,F
freeze
protection.
efmportant
-
Do not
mix
more
than
25Vo
propylene
glycol
with
water
in
an attempt
to
achieve
a
lower
than
15oF
freeze
protection,
since more concentrated mixtures
of
propylene
glycol
become
too
viscous
at
low
temperatures
and cannot
be
pumped through
the
earth
loop. Horizontal loops typically
use
GTF,
and vertical
loops
typically use propylene
-elycol.
Note
-
Always
check
State and
Local
codes
for
any special requirements
on antifreeze solutions.
Flow
rate
requirements
for
ground loops
are
hi_eher (see
Table
2)
than ground water
systems because
water
temperatures are
generally lower.
VCAUTION
-
Never
operate
with
flow
rates less
than
specified.
Low flow
rates,
or
no
flow,
may
cause
the
unit
to
shut down on
a pressure
lockout or
may
cause a
freeze
rupture
of
the heat exchanger.
elmportant
-
Figure 2
shows
that pressure/Iemperature
(P/T) ports must
be
installed
in
the
entering
and
leaving
water lines
of
the
heat
pump.
A
thermometer
can
be
inserted
into
the
P/T
ports to
check
entering
and leaving
water temperatures.
A
pressure gauge can also
be
inserted
into
these
P/T ports to
determine the
pressure
differential
between
the
entering
and leaving water.
This
pressure
6
differential
can then
be
compared to the specification
data
on
each
particular
heat
pump
to
confirm the proper
flow
rate
of
the system.
An
individually-sized ECONAR
PumpPAKrM can supply
pumping requirements
for
the
Ground
Loop
fluid,
and can
also be
used
to
pur_se
the
loop
system.
cNote
-
Refer to
instructions included
with
the
PumpPAKrM
for
detail
for
properly
purging
the
ground loop.
clmportant
-
the
pump must be installed
to
supply
fluid
into
the heat
pump.
Filling
and
purging
a
loop
system
a.re
very
important
steps
to
ensure
proper
heat
pump operation. Each
loop
must
be
purged
with
enough
flow to
ensure
two
feet per
second
flow
rate
in
each
circuit
in
the loop.
This
normally
requires
a
7Vz
to
3 HP
high-head
pump to circulate
fluid
through
the loop
to
remove
all
the
air out
of
the
loop.
Allow
the pump
to
run
10
to
15 minutes
after
the last
air
bubbles have been removed.
After
purging
is
completed,
add the calculated
proper
amount
of
antifreeze
to give
a
12oF
to
15oF
freeze
protection
After
antifreeze has
been
installed
and
thoroughly
circulated,
it
should be
measured
with
a hydrometer,
refractometer
or
any other device
to
determine
the
actual freezing
point of
the solution.
The purge
pump
can
be
used
to
pressurize the system
for
a
final
static
pressure
of
30
to
40
psig after
the
loop
pipe
has had
enough
time to
stretch.
In
order
to
achieve the
30
to 40
psig
final
pressure,
the loop may
need
to
be
pressurized
to
an
initial
pressure
of 60 to
65 psig. This
static pressure
may
vary
l0
psig
from
heating
to cooling
season,
but
the pressure
should
always
remain
above 20
psig,
so
circulation
pumps
do not
cavitate
or
pull air
into
the
system.
Econtact
your
local
installer, distributor or
factory
representative
for
more
information.
B. Ground Water Installation
A
Ground
Water
system gets
its
name
from the
open
discharge
of
water after
it
has been used
by
the
heat
pump.
A well
must be available that can
supply all
of
the
water requirements
(see
Table
2)
of
the heat pump
for
up
to
24
hours/day
on
the coldest
winter
day
plus any
other
water requirements drawing
off
of
that
same
well.
Figure
3
shows
the
necessary
components
for
ground
water
piping. First, a
bladder type
pressure
tank
with
a
"draw down"
of
at least
llz
times the
well
pump capacity
must
be
installed
on the
supply side
of
the
heat pump.
Shut-off valves and
boiler drains
on the
entering
and
leaving water lines
are necessary
for
future
maintenance.
efmportant
-
A
screen strainer
must be placed
on
the
supply
line with
a
mesh size
of 40 or 60
and
enough
surface
area
to
allow
for
particle buildup
between
cleanings.
clmportant
-
Pressure/Temperature
(p/T)
ports must
be
placed
in
the
supply and
discharge
lines
so
that
thermometers
or
pressure
gauges
can be inserted
into
the
water
stream.
I
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